Pneumatic mechanism for the application of uniform pressure to a mechanically adjustable spindle

摘要

A pneumatic mechanism for the application of uniform pressure to a mechanically adjustable spindle. The mechanism includes a support shelf with a double-acting piston attached at its non-pressure end to the support shaft. A cylinder receives the piston for telescopingly sliding movement of the piston relative to the cylinder. A lifting stop rod is connected to the pressure end of the piston and an externally threaded tube engages the pressure end of the piston and telescopingly receives the lifting stop rod. A worm wheel engages the threaded tube and a worm gear engages the worm wheel. A hand wheel is connected to the worm gear for rotating the worm gear and the worm wheel. An adjustable connection is provided between the lifting stop rod and the threaded tube permitting limited stop movement of the lifting stop rod by the piston relative to the threaded tube. Air ports for directing pressurized air against the bottom end of the piston to lift the piston and the lifting stop rod relative to the threaded tube and against the upper end of the piston to return the piston to its lowered position are provided in the cylinder.